#define _CRT_SECURE_NO_WARNINGS 1
#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

#include <math.h>
int main()
{
    char a;
    while ((a = getchar()) != EOF) {
        getchar();
        if (a >= 'A' && a <= 'z') {
            printf("YES\n");
        }
        else {
            printf("NO\n");
        }
    }
    return 0;
}